A shark attack survivor now knows what it feels like to be part bionic man. 23-year-old amputee Craig Hutto has volunteered to play guinea pig, testing a state-of-the-art prosthetic leg with powered knee and ankle joints. With early support from the National Science Foundation and continued support from the National Institutes of Health, Vanderbilt University mechanical engineer Michael Goldfarb has spent several years developing the leg, which operates with special sensors, an electric...